Steel Wheels Good, Rubber Wheels Bad? Calculating the Cost-performance Relationship for Bus-rapid-transit (BRT) and Light-rail-transit (LRT) Systems
R Clark, Transport Scotland, UK
This paper assembles capital cost and patronage information for nearly 70 LRT and nearly 50 BRT systems; identifies the situations where one mode is to be preferred over the other; and also the issue of the culture of urban transport use patterns.
Much attention has been paid to light-rail-transit (LRT) systems and the benefits they generate in terms of improved urban mobility and localised environment improvements. However, over the last twenty years, many cities have developed bus-rapid-transit (BRT) systems; so much so that BRT is now seen as a competitor to LRT as well a niche solution in its own right. This has not been welcomed by various LRT supporter groups, who regard BRT schemes as "LRT on the cheap" and are very critical of it as a result.
However, in these times of straitened governmental resources, project evaluation must be thorough and rigorous. Accordingly, this paper assembles evidence with respect to a large number of LRT and BRT systems (nearly seventy LRT schemes, in some cases reporting on separate lines within a system, and nearly fifty BRT systems); including a number of proposed schemes, in order to expand the evidence base. The data are reported for the systems in terms of their capital-cost-per-mile and annual-passengers-per-mile; this also represents a deliberate focus on passengers carried as the main indicator of system benefit, if not the only indicator. The research identifies differing patterns of both passenger demand and cost, across LRT and BRT systems; including at various combinations of per-mile demand (both by passenger and passenger-mile), per-mile cost, system scale and peak (single-direction) load. The review then identifies the circumstances under which LRT is more likely to be the appropriate mode for a particular situation, and where on the other hand BRT will be more effective - the threshold for modal choice. In particular, this means a clear identification *beforehand* of what any new investment is intended to achieve.
Finally, a number of the systems under review are set in the "bigger picture" by comparing their patronage against the overall public transport demand in their urban areas. From this indicative evidence the paper concludes by arguing that the culture of a public transport market - that which makes people in some areas much more likely to use public transport, all else held equal, than people in other areas - is a fundamental question, more important even than preferred mode, and one which needs further research attention.
Association for European Transport